Determination apparatus and method of calibrating the apparatus

ABSTRACT

The calibration reference standard of a determination apparatus is determined and the error model is found and the determination results from which the effects of systematic error have been removed are displayed. If the operator is satisfied with these determination results, calibration is terminated. Moreover, if the operator is not satisfied with these determination results, the desired parameter of the calibration reference standard is re-determined, the error coefficient is found and the determination results from which the systematic error has been removed are immediately re-displayed. These determination results are retained until calibration is terminated and if re-determination of a calibration reference standard has been performed during the calibration operation, the determined values are retained so that the most recent determination results can be referenced.

FIELD OF THE INVENTION

The present invention relates to a determination apparatus comprising acalibration function, and in particular pertains to a determinationapparatus having two or more determination electrodes with which workefficiency is improved during calibration.

BACKGROUND OF THE INVENTION

Many determination apparatuses have imperfections, including deviationsbetween the determined values of these apparatuses and the actualvalues. Therefore, determination apparatuses are produced such that thedetermination apparatus is calibrated prior to determination of a deviceunder test (DUT hereinafter), so that the effects of systematic errorcan be removed from the determined value. Systematic error ishereinafter referred to as error and error coefficient.

A conventional calibration method and its procedure will now bedescribed using a network analyzer as an example of the determinationapparatus.

FIG. 1 is a schematic drawing of a two-port network analyzer 100.Network analyzer 100 comprises a CPU 120, a memory 130, which is anexample of a memory, an input device 140, a determination device 150,and a display 160, which is an example of an output means. Furthermore,these structural elements are connected together by a bus 110. CPU 120exchanges data with memory 130, input device 140, determination part150, or display part 160 and processes the data as needed. Memory 130stores information on settings for network analyzer 100, determinedvalues obtained by determination device 150, etc. Input device 140receives commands from outside network analyzer 100. Determinationdevice 150 has a port A and a port B that are the determinationterminals, and determines the incident signal power and reflected signalpower. Furthermore, the incident signals are output signals at the portsand the reflected signals are input signals at the ports.

A two-port device is connected between port A and port B of this type ofnetwork analyzer 100. When the forward and backward network propertiesof this device are determined, there are 12 systematic errors presentrelated to signal leak, signal reflection, and frequency response.

The TRL (Through-Reflect-Line) calibration method is one calibrationmethod whereby the effect of these errors is removed from the determinedvalues. The TRL calibration method is characterized in that three typesof calibration reference standards are used through a reflect, and aline standard. It is possible to remove the effects of ten errors withtwo-port calibration, and it can be used for non-coaxial environmentsand on-wafer determinations. Furthermore, the reflect reference standardis either an open reference standard or a short reference standard.

FIG. 2 is a flow chart showing the procedure of the TRL calibrationmethod as conducted with network analyzer 100. In step P21, data frominput device 140 are received and property values are set for thecalibration reference standard that will be used in calibration.Incidentally, both port A and port B are used to determine thecalibration reference standards. In step P22, determination part 150determines the calibration reference standard connected to port A andport B and CPU 120 receives these determined values from determinationdevice 150 and stores them in memory 130.

By means of the TRL calibration method, it is necessary to determine 12parameters of the calibration reference standard in the case of two-portcalibration. Consequently, processing is performed in step P23 to decidewhether or not all of these determined values have been obtained. StepP22 is repeated until all determined values are obtained.

Moreover, in step P24, CPU 120 references the determined values of 14parameters, finds the values of 10 errors, and stores these error valuesin memory 130 as error coefficients. Finally, the determined values ofthe 14 parameters stored in the memory are erased. Network analyzer 100can output determined values of the DUT, wherein the effects of theerrors found have been removed (i.e., the corrected determined values)after calibration by the above-mentioned procedure.

However, there are cases in which it is impossible to accurately findthe error due to poor connection of calibration reference standards ormis-connection of calibration reference standards attributed to thenumber of determination terminals, etc., after calibration has beenperformed and the calibration reference standard must therefore bere-determined. Whether or not the error has been accurately found can beconfirmed by observing the corrected determined values. However,according to the conventional procedure, the corrected determined valuescan only be observed after calibration. Once calibration has beenperformed, all of the determined values for the parameters of thecalibration reference standards are erased and the specific parametervalues have to be re-determined to confirm accuracy thereof, resultingin poor calibration work efficiency. In recent years, the number ofports in the determination devices and DUTs has increased and as aresult, the time for re-calibration has increased. This problem issignificant.

SUMMARY OF THE INVENTION

The object of the present invention is to solve the above-mentionedproblems of the prior art, its object being to reduce the number ofprocesses when re-determination of calibration reference standards isnecessary by outputting the determined values of desired parameters fromwhich the effects of error have been removed during calibration work.

Moreover, another object is to prevent the waste of memory resourceswhen determined values of the parameters of calibration referencestandards are stored and to prevent workers from being confused by theco-existence of newly determined values and old determined values whencalibration is performed again by rendering the determined values of theparameters of calibration reference standards unusable when calibrationis interrupted or terminated.

Yet another object is to make it easy to verify error coefficientsobtained by calibration and to respond when poor error coefficients areobtained when N number of the determination terminals are to becalibrated by calibrating determination terminals for each combinationof determination terminals obtained by selecting M number ofdetermination terminals less than N from N number of the determinationterminals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of a network analyzer capable ofcalibration by conventional methods;

FIG. 2 is a flow chart showing the calibration procedure by aconventional method;

FIG. 3 is a schematic drawing of a network analyzer capable ofcalibration by the method of the present invention;

FIG. 4 is a drawing showing an exemplary detailed internal structure ofthe determination device of a network analyzer capable of calibration bythe method of the present invention;

FIG. 5 is a flow chart showing the calibration procedure by the methodof the present invention;

FIG. 6 is a drawing showing an exemplary screen displayed by thecalibration program according to the method of the present invention;

FIG. 7 is a drawing showing an exemplary screen displayed by thecalibration program according to the method of the present invention;

FIG. 8 is a drawing showing an exemplary screen displayed by thecalibration program according to the method of the present invention;

FIG. 9 is a drawing showing an exemplary screen displayed by thecalibration program according to the method of the present invention;

FIG. 10 is a drawing showing an exemplary screen displayed by thecalibration program according to the method of the present invention;and

FIG. 11 is a drawing showing an exemplary screen displayed by thecalibration program according to the method of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A first embodiment of the present invention is a method of calibrating adetermination apparatus having determination terminals and a memory. Themethod of calibration includes removing the effects of an error from thedesired determined value of a desired parameter and outputting thedetermined value and using a calibration reference standard with which,the desired parameter of the calibration reference standard can bere-determined. The re-determined value can be stored in the memory meanswhile keeping as is the determined value of the parameter of the storedcalibration reference standard.

Moreover, by means of a second object of the invention the determinedvalue of the parameter of the calibration reference standard is renderedunusable when calibration is interrupted or terminated.

Furthermore, the third object of the invention is a method ofcalibrating a determination device comprising determination terminalsusing a calibration reference standard with which when the N number ofthe determination terminals are to be calibrated, determinationterminals are calibrated for each combination of determination terminalsobtained by selecting M number of determination terminals less than theN from N number of the determination terminals.

The present invention will now be described based on the exemplarydetermination device shown in the attached drawings. The example is afour-port network analyzer calibrated by the method of the presentinvention. An illustrative schematic drawing is shown in FIG. 3.

Network analyzer 300 in FIG. 3 is an example of a determinationapparatus. It comprises a CPU 320, which is an example of a controller;a memory 330, an example of a memory means; input device 340; adetermination device 350, an example of a determination means; a display360, an example of an output means, and a hard disk drive 370 (HDDhereinafter), an example of a recording medium. Furthermore, thesestructural units are connected by a bus 310. CPU 320 controlsdetermination device 350 and display 360, etc., and calibrates networkanalyzer 300 by performing the calibration program read from HDD 370.Memory 330 stores the information on settings of network analyzer 300and determined values obtained by determination part 350, etc. Althoughnot illustrated, a keyboard or mouse, etc., is connected and inputdevice 340 receives commands from the outside. Determination device 350comprises port 1, port 2, port 3, and port 4 that are examples ofdetermination terminals used for determining incident signal power andreflected signal power at each port.

An illustrative drawing of the internal structure of determinationdevice 350 is shown in FIG. 4. Determination device 350 comprises signalsource generator SG; switches SW₁, SW₂, SW₃, and SW₄, referencereceivers R₁, R₂, R₃ and R₄ for determining incident signal power; andtest receivers T₁, T₂, T₃, and T₄ for determining reflected signalpower.

Signal generator SG outputs the base signals for determination. Theamplitude and frequency of these output signals are variable.

Switch SW₁ is connected to signal generator SG and port 1 and eitherdirects port 1 to signal generator SG or closes that port. Switch SW₂ isconnected to signal generator SG and port 2 and either directs port 2 tosignal generator SG or closes that port. Switch SW₃ is connected tosignal generator SG and port 3 and either directs port 3 to signalgenerator SG or closes that port. Switch SW₄ is connected to signalgenerator SG and port 4 and either directs port 4 to signal generator Gor closes that port. The switches operate so that when one switchdirects a port to signal generator SG, the other 3 switches close theports.

Test receiver T1 is connected to port 1 with directional coupler C_(T1)therebetween and determines incident signal power at port 1. Referencereceiver R₁ is connected to port 1 with directional coupler C_(R2)therebetween and determines reflected signal power at port 1. Testreceiver T₂ is connected to port 2 with directional coupler C_(T2)therebetween and determines incident signal power at port 2. Referencereceiver R₂ is connected to port 2 with directional coupler C_(R2)therebetween and determines reflected signal power at port 2. Testreceiver T₃ is connected to port 3 with directional coupler C_(T3)therebetween and determines incident signal power at port 3. Referencereceiver R₃ is connected to port 3 with directional coupler C_(R3)therebetween and determines reflected signal power at port 3. Testreceiver T₄ is connected to port 4 with directional coupler C_(T4)therebetween and determines incident signal power at port 4. Referencereceiver R₄ is connected to port 4 with directional coupler C_(R4)therebetween and determines reflected signal power at port 4.

When TRL calibration is performed with network analyzer 300, informationrelating to calibration reference standards, the determined values ofparameters of calibration reference standards, and systematic errorsfound from the determined values of these parameters are stored inmemory 330. The information relating to calibration reference standardsincludes the amount of delay and property impedance of the throughreference standard; the type, amount of delay and property impedance ofthe reflect reference standard; and the amount of delay, propertyimpedance and two frequencies showing the frequency of use range of theline reference standards. TABLE 1 Array structure of informationrelating to calibration reference standards Through reference standard:Amount of delay, property impedance Reflect reference standard: Amountof delay, property impedance, type of reference standard Line referencestandard 1: Amount of delay, property impedance, minimum frequency,maximum frequency Line reference standard 2: Amount of delay, propertyimpedance, minimum frequency, maximum frequency

The type of reflect reference standard is either an open referencestandard or a short reference standard as previously mentioned.Moreover, the frequency range within which one line reference standardcan be used is limited and therefore, in the present example, a broadfrequency range is guaranteed by using two different line referencestandards.

The most systematic errors present when a four-port device is determinedusing network analyzer 300 is 48 errors. The error value of 36 of 48systematic errors can be found by TRL calibration. Again, the value of asystematic error is also called the error coefficient. The followingerror coefficients are included in the 36 error coefficients:directional [Ed], source matching [Es], and reflection tracking [Er],and load matching [El] and transmission tracking [Et] for a pair of twoports selected from the four ports. Network analyzer 300 performsdeterminations for multiple points within the determination frequencyrange and therefore, groups of 36 error coefficients corresponding tothis number of determination frequency points are stored in memory 330.TABLE 2 Array Structure of Error Coefficients Directional: Ed [n] Sourcematching: Es [n] Load matching: El [n * n] Reflection tracking: Er [n]Transmission tracking: Et [n * n](During n port calibration)

Furthermore, load matching and transmission tracking are stored in ]N *N] arrays so that they can be easily referenced from the program.

In addition, it is necessary to determine 64 parameters of a calibrationreference standard in order to find 36 error coefficients of onedetermination frequency point. The specifics are as follows:

Four S parameters, which are transmission coefficients and reflectioncoefficients determined at each port for each group when the throughreference standard and line reference standard have been connected to 6combinations of ports when two of four ports are selected. That is, thepairs of ports 1-2, ports 1-3, ports 1-4, ports 2-3, ports 2-4, or ports3-4. Two parameters that are switch matching parameters determined withrespect to each port of each pair when the through reference standardhas been connected to the above-mentioned 6 types of port groups. One Sparameter, which is a reflection coefficient determined at each portwhen the reflect reference standard has been connected to each of the 4ports. TABLE 3 Array Structure of Determination Parameters Throughreference standard: Thru [C] [4] Reflect reference standard: Reflect [n]Line reference standard: Line [C] [4] Switch matching: SwitchMatch [C][2](During n port calibration)

Here, C is a combination nC₂ of two selected from n number.Incidentally, as with the error coefficients, these groups ofdetermination parameters are stored in memory 330 corresponding to thenumber of determination frequency points.

The procedure of processing the program for calibration with networkanalyzer 300 made as described above will now be described whilereferring to the flow chart in FIG. 5.

In step P41, data are received from input device 440 and the informationrelating to the calibration reference standards that will be used forcalibration are set. An example of the screen displayed by display 360relating to step P41 is shown in FIG. 6. In FIG. 6, dialog box 600comprises a list box for selecting the channel and port, a “DefineCalkit” button for opening the setting dialog box of the calibrationreference standard, a “Measure>” button for opening the determinationdialog box for the calibration reference standard, and a message box.These buttons and list box, etc., are linked to a mouse that isconnected to an input device and is operated by a pointer, etc.,displayed on a screen by display 360. Network analyzer 300 can displaymultiple separate windows for displaying determination results. Thesewindows are called channels in the present example. There are caseswhere the operator must calibrate the necessary port for each channelwhen displaying determination parameters that are different for eachchannel. Consequently, the channels and ports can be selected in dialogbox 600. For instance, a number from 1 to 9 can be selected from thelist for the channels. Moreover, the port, which is the calibrationsubject, is selected by selecting any pair of ports 1-2, 1-3, 1-4, 2-3,2-4, or 3-4 when this number is 2, selecting any group of ports 1-2-3,1-2-4, 1-3-4, or 2-3-4 when this number is 3, and selecting all portswhen this number is 4.

The setting dialog box for the calibration reference standard, which isdisplayed by pushing the “define Calkit” box, is shown in FIG. 7. InFIG. 7, dialog box 700 comprises an input box, a radio button, and checkboxes for setting information relating to calibration referencestandards. It is not always necessary to use two line referencestandards and therefore, the line reference standard that will be usedcan be selected with the check boxes.

With respect to the type of reflection reference standard, either theopen reference standard or the short reference standard is selected withthe radio button. Other setting information related to the calibrationreference standard, such as the amount of delay, etc., is set byinputting numbers into the input box. Dialog box 700 has a “Save” buttonfor storing information relating to the calibration reference standardin a storage medium, such as HDD 370, etc., and a recall button thatrecalls the setting information stored in the storage medium or adefault button that recalls pre-determined settings. Once the settingsare complete the information that was set in dialog box 700 is stored inmemory 330 and dialog box 700 is closed by pushing “Close.”

When information relating to the channel, port and calibration referencestandard has been properly set, the characters “ok” are displayed in themessage box and the “Measure>” button can be pushed. The “Measure>”button cannot be used until information relating to the calibrationreference standard has been properly set. The channel and port selectiondetails can be changed, but the “define Calkit” button cannot be used,even after the “ok” characters are displayed in the message box. Whenthe “Measure>” button is pushed, the channel and port information thathave been selected are stored in memory 330, dialog box 600 is closed,and processing proceeds to step P42.

In step P42, the dialog box relating to determination of the calibrationreference standard is displayed by display 360 and this calibrationreference standard is determined. An example of the screen displayed bydisplay part 360 relating to step P42 is shown in FIG. 7. Dialog box 810lists ports or groups of ports that are to be connected to therespective calibration reference standard based on the port that hasbeen selected with dialog box 600. As becomes clear when referring tothe dialog boxes in FIGS. 6 and 7, network analyzer 300 is set so thattwo-port calibration between ports 1 and 2 is performed at adetermination frequency range of 1.0 to 8.5 GHz. Therefore, port 1 orport 2 or ports 1-2 are indicated in the group of calibration referencestandards in dialog box 810 as the ports that are to be connected. Forinstance, two buttons are displayed in the “Reflection” box, which showsthe connection of the reflect reference standard, and the respectivenumber that stands for the port no., either [1] or [2], is displayed.For instance, when the reflect reference standard is connected to port 1and button [1] of the “Reflection” box is pushed, the determination ofthe reflect reference standard is performed at port 1 and the determinedvalue is stored in memory 330. A button that displays the port or groupof ports to which another calibration reference standard is to beconnected is given for another group of calibration reference standards.The color of these buttons changes when these buttons are pushed and therelated determination has been completed.

In step P43, evaluation and branch processing are performed in order tocontinue the processing in step P42 until all determinations necessaryfor calibration are completed. Dialog box 810 has the “Update CalCoef”button for finding the error coefficient and reflecting this in theremoval of the effects of errors in subsequent determinations. Thisbutton can be pushed when all determinations necessary for calibrationare completed. Furthermore, the color of all of the buttons listed ineach group of calibration reference standards in dialog box 810 changeswhen all determinations are completed. This type of dialog box is shownin FIG. 9. The “Update CalCoef” button cannot be used until alldeterminations necessary for calibration have been completed.

Dialog box 810 has a “Close” button and therefore, the calibrationoperation can be interrupted. When the calibration operation isinterrupted, channel and port selection information and information onsettings for calibration reference standards are saved and determinedvalues obtained before interruption are all erased. Moreover, dialog box810 has a “<Setup” button and therefore, it is possible to re-select thechannels and ports or re-set the information relating to the calibrationreference standards. The determined values of parameters of thecalibration reference standards and colors of the buttons are notinitialized or changed, even if re-selection or re-setting areperformed.

Now, when the “Update CalCoef” button is pushed, program processingproceeds to step P44.

In step P44, CPU 320 calculates the error coefficients while referringto the determined values of parameters that have been stored in memory330 and stores these coefficients in memory 330. That is, the systematicerrors are found. In step P45, CPU 320 outputs the determined values ofdesired parameters from which the effects of the error have been removedto display 360 while referring to the error coefficients that have beenstored in memory 330 and the determined values obtained fromdetermination part 350. The error that will be removed in the short termalso includes a drift error.

Examples of output of display 360 are shown in FIGS. 10 and 11. Result910 of the determination of a desired parameter when the errorcoefficient cannot be reliably found is shown in FIG. 10. On the otherhand, result 920 of the determination of the desired parameter when theerror coefficient can be reliably found is shown in FIG. 11. Bothdetermination results 910 and 920 are results of the determination ofthe transmission coefficient S21 from port 1 to port 2 when the throughreference standard has been connected between port 1 and port 2. Whetheror not the error coefficient found is valid can be evaluated, forinstance, by observing the amplitude of the determination results (stepP45).

As is clear from FIG. 10 or FIG. 11, the dialog box for determining thecalibration reference standard also displays the determination resultsand therefore, it is possible to re-determine only the desired parameterfrom among the parameters of calibration reference standards that havealready been determined. For instance, if the error coefficient that hasbeen found is incorrect, a button displaying the port no. that is listedin dialog box 830 is selected and the desired parameter of thecalibration reference standard can be re-determined so that thedetermination results in FIG. 11 can be obtained. As with the dialog boxin FIG. 9, dialog box 830 has an “Update CalCoef” button and therefore,when the “Update CalCoef” button is pushed after re-determination, a newerror coefficient is found and determination results that reflect thiserror coefficient are displayed.

When the calibration program described in detail above using the flowchart in FIG. 5 is processed, the results of determining the desiredparameter as indicated at that time are displayed in the background ofthe dialog box that is displayed and as with ordinary determinations,the desired parameter can be indicated or the pattern used to displaythe results of determining this parameter can be changed during theprocessing of the same program. For instance, when the determinationresults are displayed in a window displayed in display 360, they can bedisplayed with a waveform or numbers that display a list or in anotherform, or the scroll bar of the window can also be operated when thedetermination results are displayed in a list. Other settings relatingto the determinations can be changed during the processing of thecalibration program.

Dialog box 840 in FIG. 11 is the same as dialog box 830 in FIG. 10 andhas a “Close” button. Therefore, if it is judged that the errorcoefficient that has been found is valid, calibration can be terminatedby pushing this “Close” button. The channel and port selectioninformation and information on setting the calibration referencestandards are retained, even if calibration is terminated, but alldetermined values obtained before termination will be erased.

Now, as previously mentioned, dialog box 810 has a “<Setup” button andtherefore, it is possible to re-select the channels and ports or tore-set the information relating to the calibration reference criteria,and the determined values of the parameters of the calibration referencestandards and colors of the buttons will not be initialized or changed,even if re-selection or re-setting is performed. This is important toimproving calibration operation efficiency because it makes it possibleto divide n port calibrations into multiple two-port calibrations thatcan be performed in steps.

For example, in the case of three-port calibration of ports 1-2-3, it ispossible to switch between two-port calibration for ports 1-2 andtwo-port calibration for ports 1-3 during the three-port calibration ofports 1-2-3. When compared to 3-port calibration, the factors thataffect the results of determining calibration reference standards, suchas the connected ports and connection status of the calibrationreference standards, etc., are limited with 2-port calibration, andtherefore, it is easier to confirm whether or not an error coefficientfound is valid and to respond if the error coefficient found is invalid.

As long as the above-mentioned calibration program is stored on arecording medium so that network analyzer 300 can execute this program,this recording medium can be presented separate from network analyzer300, even if it is housed in network analyzer 300. For instance, it ispossible to record this program on a storage medium such as a CDROM,floppy disk, memory card, external HDD, etc., and load the program fromthis storage medium into network analyzer 300. Moreover, it is, ofcourse, possible to record this program on a ROM and load it intonetwork analyzer 300.

By means of the present invention that was described above in detail, itis possible to reduce the number of processes when re-determination ofcalibration reference standards is necessary by outputting thedetermined values of desired parameters from which the effects of errorhave been removed during calibration work.

Moreover, it is also possible to prevent waste of memory resources inwhich determined values of the parameters of calibration referencestandards are stored and to prevent workers from being confused by theco-existence of newly determined values and old determined values whencalibration is performed again by rendering the determined values of theparameters of calibration reference standards unusable when calibrationis interrupted or terminated.

Furthermore, it is possible to easily verify error coefficients obtainedby calibration and respond when poor error coefficients are obtainedwhen N number of the above-mentioned determination terminals are to becalibrated by calibrating determination terminals for each combinationof determination terminals obtained by selecting M number ofdetermination terminals less than the N from N number of theabove-mentioned determination terminals.

1. A determination apparatus comprising: a determination device having aplurality of determination terminals; a controller for selecting atleast one of said plurality of determination terminals, determining acalibration reference standard, and setting of a property value of saiddetermined calibration reference standard; a memory for storing aparameter of said determined calibration reference standard and adetermined value for said parameter as determined by said determinationdevice; wherein said determination device determines an error of saiddetermined value of said parameter, said error being stored in saidmemory, said determination device outputting said determined value afterremoving an effect said error therefrom, and obtaining and storing are-determined value for said parameter while maintaining said determinedvalue of said parameter of said calibration reference standard in saidmemory.
 2. The device in claim 1, wherein said determination devicestores said re-determined value for said parameter in said memory, whilemaintaining said property value of said determined calibration referencestandard in said memory.
 3. The device in claim 1, wherein saidcontroller renders unusable said determined value of said parameter ofsaid calibration reference standard in said memory.
 4. The device inclaim 1, wherein said determination device is a network analyzer havingtwo or more determination terminals.
 5. A method of calibrating adetermination apparatus having determination terminals and a memoryusing a calibration reference standard, said method comprising:selecting at least one of said determination terminals and a calibrationreference standard; setting a property value of said selectedcalibration reference standard; selecting a parameter of saidcalibration reference standard; storing a determined values of saidparameters of said calibration reference standard in said memory;referencing said determined value of said parameter of said calibrationreference standard stored in said memory; determining an error of saiddetermined value of said parameter; outputting said determined valueafter removing an effect of said error; re-determining a value for saidparameter of said calibration reference standard; and storing saidre-determined value in said memory while maintaining said determinedvalue of said the parameter of said calibration reference standard insaid memory.
 6. The method in claim 5, further comprising the step of:reselecting a desired parameter of said calibration reference standard;and storing a re-determined value of said desired parameter in saidmemory while maintaining said determined values of said parameter ofsaid calibration reference standard in said memory.
 7. The method inclaim 5, further comprising: rendering said determined values of saidparameter of said calibration reference standard in said memory unusablewhen any of the method steps are interrupted or terminated.
 8. A methodof calibrating a determination apparatus having a plurality ofdetermination terminals using a calibration reference standard, saidmethod comprising: selecting at least one of said determinationterminals and a calibration reference standard; setting a property valueof said selected calibration reference standard; selecting a parameterof said calibration reference standard; referencing said determinedvalue of said parameter of said calibration reference standard stored insaid memory; determining an error of said determined value of saidparameter; outputting said determined value after removing an effect ofsaid error; re-determining a value for said parameter of saidcalibration reference standard; and storing said re-determined value insaid memory while maintaining said determined value of said parameter ofsaid calibration reference standard in said memory of the determinationapparatus under test being connected to a desired terminal of said atleast one determination terminals, wherein when calibrating N number ofsaid determination terminals, the determination apparatus calibrates apre-selected number of determination terminals for each combination ofsaid determination terminals obtained by selecting M number ofdetermination terminals less than the N from N number of saiddetermination terminals.
 9. The method in claim 8, wherein saiddetermination apparatus is a network analyzer having at least two ormore determination terminals.
 10. A recording medium having computerreadable program instructions embodied thereon for controllingcalibration of a determination apparatus comprising determinationterminals and memory using a calibration reference standard, saidrecording medium comprising: program instructions for selecting saiddetermination terminals and a calibration reference standard; programinstructions for setting a property value of said selected calibrationreference standard; program instructions for determining a parameter ofsaid selected calibration reference standard; program instructions forstoring said determined value in said memory; program instructions forreferencing said determined value of said parameter of said calibrationreference standard stored in said memory; program instructions fordetermining an error from said referenced determined value of saidparameter of said calibration reference standard; program instructionsfor outputting said determined value of this desired parameter afterremoving an effect of said error; program instructions forre-determining said parameter of said calibration reference standard;and program instructions for storing said re-determined value in saidmemory while maintaining said determined value of said parameter of saidcalibration reference standard.
 11. The recording medium in claim 10,further comprising; program instructions for re-determining saidparameter of said selected calibration reference standard and storingsaid re-determined value in said memory while maintaining saiddetermined values of said parameter of said calibration referencestandard in said memory.
 12. The recording medium in claim 10, furthercomprising: program instructions for rending unusable said determinedvalue of said parameter of said calibration reference standard in saidmemory when any steps are interrupted or terminated.
 13. A recordingmedium having a computer readable program instructions embodied thereonfor controlling calibration of a determination apparatus comprisingdetermination terminals and memory using a calibration referencestandard, said program comprising: program instructions for selectingsaid determination terminals and a calibration reference standard;program instructions for setting a property value of said selectedcalibration reference standard; program instructions for determining aparameter of said selected calibration reference standard; programinstructions for storing said determined values in said memory; programinstructions for referencing said determined values of said parameter ofsaid calibration reference stored in said memory; program instructionsfor determining an error from said referenced determined value of saidparameter of said calibration reference standard; program instructionsfor outputting said determined value of this desired parameter afterremoving an effect of said error; program instructions forre-determining said parameter of said calibration reference standard;and program instructions for storing said re-determined value in saidmemory while maintaining said determined values of said parameter ofsaid calibration reference standard, wherein when calibrating N numberof said determination terminals, the recording medium having computerreadable program instruction thereon calibrates said determinationterminals of the determination apparatus for each combination of saiddetermination terminals obtained by selecting M number of determinationterminals less than the N number from N number of said determinationterminals.